Dr Dan Jones

About me

I entered oceanography via physics and applied mathematics. My typical regions of study are the Southern Ocean and (recently) the North Atlantic, which are both
climate-relevant regions that feature strong exchanges of heat and carbon between the atmosphere and the deep ocean. My toolbox includes a hierarchy of approaches, from simple pen-and-paper representations to high-resolution adjoint models.

Outside of work, I spend time with my wife and young son, squeezing in some reading and guitar playing where possible.
We live in a village just outside of Cambridge, UK.

Background

Earth's oceans have an enormous impact on global and regional climate. For example, the ocean contains more than 90% of the extra heat present in the climate system due
to global warming. However, the mechanisms involved in the exchange of heat and carbon between the ocean and atmosphere, and how they may change in the future, are still poorly understood.

At a few distinct locations on Earth, the natural injection of heat and carbon into the interior ocean, called subduction, is particularly intense.
Once trapped in the interior ocean, the subducted heat and carbon can remain there for decades to centuries, potentially slowing global surface warming.
These atmosphere-ocean exchange windows are typically found in the Southern Ocean and the high-latitude North Atlantic, which feature exceptionally deep mixing between the surface and the interior ocean.
For example, the Eastern Pacific pathway (shown below) is a relatively rapid and efficient export pathway (link to research article) for the exchange of water between the surface and the subtropical interior.
In order to understand and predict future climate change, we have to understand what controls the location and intensity of these relatively narrow exchange windows.

Ocean circulation, dynamics, and climate

I use a combination of basic physics, mathematics, and numerical modeling to better understand the behavior of the ocean, including its sensitivity
to other components of the climate system. For example, I use ocean adjoint models to uncover potentially hidden ways in which the ocean
can respond to changes in the atmosphere. In a recent study, we found that the heat content of the Labrador Sea, a region of deep convection in the
North Atlantic, is sensitive to wind stress along the relatively remote West African shelf. This kind of large-scale, remote connection is an important feature
of the climate system that we need to better understand. For more information, including an introduction to adjoint sensitivity experiments, see our
article in JGR-Oceans, which is also available
as an open access preprint.
The study is also summarized in this plain language blog post

Machine learning: clustering

I have recently started applying various unsupervised clustering algorithms to oceanographic data in order to better understand its structure.
In particular, my students and I have applied Gaussian mixture modelling, a machine learning technique, to Southern Ocean temperature profiles.
Our initial results are promising, as we describe in this preprint (in revision for JGR-Oceans). Clustering
may offer a new, objective way to identify structures in both observed and simulated climate data, ultimately enhancing our ability to understand the climate system.

Air-sea gas exchange

The exchange of carbon dioxide, oxygen, and other gases at the air-sea interface has an enormous impact on surface climate across a wide range of timescales.
Despite its critical importance to the climate system, the sensitivity of gas exchange to winds, biogeochemical parameters, and other factors remains poorly understood.
Using simple analysing and modeling techniques, we developed a simple model of air-sea gas exchange efficiency to
help understand the large-scale, persistent disequilibrium of carbon dixodie between the atmosphere and ocean.

Linking physics, biogeochemistry, and ecology

Ocean circulation connects geographically distinct ecosystems across a wide range of spatial and temporal scales via exchanges of physical properties and biogeochemical tracers.
Non-local processes can be especially important for ecosystems in the Southern Ocean, where the Antarctic Circumpolar Current (ACC) transports propertie across ocean basins through
both advection and mixing. In collaboration with ecologists, I use physical, biogeochemical, and ecological data to better understand what sets the location of top predator habitats (work in revision).

Selected university courses taught

Teaching philosophy

I practice learner-centered teaching following the MIT Active Learning model.
I have implemented this approach in numerous university courses. While teaching at Georgia Southern University, I restructured the Environmental Physics course
around active learning.

Podcast

I love working with scientists. They are some of my favorite people. And ultimately, science only gets done because people step up and get to it.
I decided to celebrate some of these fine individuals by inviting them to share relaxed, casual conversations about their lives and work. The results
are captured in my podcast, Climate Scientists, which is available for free on ten platforms (and counting).

Description: Using a numerical modelling technique called adjoint modelling, we examined the factors that control the heat distribution the recently ventilated Southeast Pacific sector of the Southern Ocean.
We were somewhat surprised to find that the distribution was only weakly sensitive to high-latitude atmospheric processes.

Description: We used unsupervised classification, a machine learning technique, to objectively identify groups of Southern Ocean temperature measurements with similar vertical structures.
This approach may be useful for automatically locating structures in climate data, which is important given the ever increasing volume of observational and model data.

Description: Using a numerical modelling technique called adjoint modelling, we examined the factors that control the heat content of the climatically-important Labrador Sea, which is a site of heat and carbon exchange between the surface and the deep interior ocean.
We found and tested an unexpected connection between Labrador Sea heat content and winds along the remote West African shelf.

Description: Using a high-resolution numerical model of the Southern Ocean, we identified and examined a relatively efficient pathway for transporting heat and carbon from the surface ocean into the interior ocean, where it can potentially be sequestered for many decades to centuries.

Our paper on the long-term response of the SO to wind stress changes:D.C. Jones, T. Ito, and N.S. Lovenduski (2011),
The transient response of the Southern Ocean pycnocline to changing atmospheric winds,
Geophysical Research Letters, 38, L15604, doi:10.1029/2011GL048145.
Article

Description: Observations from the last several decades show a significant increase in the strength of westerly winds over the Southern Ocean, but an appreciable change in the tilt of constant density surfaces (isopycnals) has not yet been detected there.
We used an idealized numerical model to demonstrate that it may take many decades to centuries for Southern Ocean density structures to respond to changes in wind stress, due to coupling with the rest of the ocean.

Contact

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